Funsho Kolawole - Academia.edu (original) (raw)

Papers by Funsho Kolawole

Annals of Science and Technology

Characterization of synthesized cassava stem nanoparticles (CSNPs) was carried out using SEM/EDX ... more Characterization of synthesized cassava stem nanoparticles (CSNPs) was carried out using SEM/EDX and Gwyddion software, XRD and TEM for cassava stem (CS) ball milled at 36, 48, 60 and 72 h. The morphology study was done using SEM and the Gwyddion software was used to determine the particle size from the SEM images. The particle size range for the un-milled cassava stem (CS) was between 1.02+ 0.05 to 19.99+ 1.00 µm. After milling for 36, 48, 60 and 72 h the average particle size were 0.93+0.05 µm, 128.20+ 6.41, 111.20+ 5.56, 101.20 + 5.06 nm respectively. The particle size of 11.83+0.59 nm was obtained by XRD using Scherrer equation after milling for 72 h and the XRD results revealed the presence of compounds such as SiO 2 , CaCO 3 , Ca 3 SiO 5 and Al 2 O 3. Furthermore, TEM was used to determine nanoparticles after milling for 72 h and the particle size ranged from 8.35 + 0.42 to 51.74 + 2.59 nm for cassava stem nanoparticles (CSNPs) and EDX result showed trace element of O,Si, Ca, Al, K, Ti, Fe andP in the CS milled for 72 h.

MRS Advances

Synthesis and characterization of cassava bark nanoparticles (CBNPs) was carried out using ball m... more Synthesis and characterization of cassava bark nanoparticles (CBNPs) was carried out using ball milling at 36, 48, 60 and 72 hours. The morphology study was done using SEM and the Gwyddion software was used to determine the particle sizes from the SEM images. The particle distribution for the un-milled cassava bark (CB) was between 1.25 + 0.06 to 19.92 + 1.00 µm, while after milling for 36, 48, 60 and 72 hours the average particle size were 4.07 + 0.20, 4.00 + 0.20 µm, 80.90 + 4.05, 74.50 + 3.73 nm respectively. 13.68 + 0.68 nm was obtained by XRD using Scherrer equation after milling for 72 hours and the XRD results revealed the presence of compounds such as SiO2, CaCO3 and KAlSi3O8. TEM was used to determine nanoparticle size distribution after milling for 72 hours and the particle size ranged from 9.73 + 0.49 to 114.60 + 5.73 nm for cassava bark nanoparticles (CBNPs), EDX results showed trace element of Si, Ca, K, Fe, Al, O in the CB milled for 72hours.

Tribology in Industry, 2017

Characterization of synthesized cassava leaf nanoparticles (CLNPs) was carried out using SEM/EDX ... more Characterization of synthesized cassava leaf nanoparticles (CLNPs) was carried out using SEM/EDX and Gwyddion software, XRD and TEM for cassava leaves (CL) ball milled at 36, 48, 60 and 72 hours. The morphological study was done using SEM and the Gwyddion software was used to determine the particle sizes from the SEM images. The particle size range for the un-milled cassava leaves (CL) was between 1.88 + 0.09 to 19.53 + 0.98 µm. After milling for 36, 48, 60 and 72 hours the average particle sizes were 4.96 + 0.25, 3.51 + 0.18 µm, 86.90 + 4.35, 74.50 + 3.73 nm respectively. Crystallite size of 23.94 + 1.20 nm was obtained by XRD using Scherrer equation after milling for 72 hours and the XRD results revealed the presence of compounds such as SiO2, CaCO3, Ca2(SO4)2H2O and CaC2O4(H2O). Furthermore, TEM was used to determine nanoparticles after milling for 72 hours and the particle size ranged from 9.16 + 0.46 to 58.20 + 2.91 nm for cassava leaf nanoparticles (CLNPs) and EDX results showed trace element of O, Si, Ca, K, Fe and S in the CL milled for 72 hours. FTIR was also carried out to determine the nature of bond that exist in the organic compounds in CLNPs and GCMS analysis was used to reveal the organic compounds that were present in CLNPs. Anti-Corrosion coatings reduces corrosion activities to the bearest minimum.

SN Applied Sciences

The density, tensile properties at different gauge lengths, Weibull modulus, and water absorption... more The density, tensile properties at different gauge lengths, Weibull modulus, and water absorption at elevated temperatures of coir fibres of Sri Lanka are presented. The tensile strength and stiffness of these fibres were found to decrease by 51.0 and 68.0% respectively as the gauge length of the coir fibres increased from 20 to 100 mm at a constant cross-head displacement rate of 1 mm/minute. The elongation at break of these fibres increased from 33.3 to 62.5% as the gauge length increased from 20 to 100 mm. The porosity of the fibres is in the range of 32.9–48.1% with an average pore count of 130–475 and average cell diameter of 6.8–13.7 µm within the studied diameter range of 0.162–0.313 mm. The porosity of coir fibres was found to increase as the diameter increased. TGA and scanning electron microscopy of failed samples were conducted to analyse the failure modes and to observe the trend in changes in the mechanical properties.

Journal of The Institution of Engineers (India): Series D

Waste and Biomass Valorization

In this study, the effects of austempering on the microstructure, mechanical properties (micro ha... more In this study, the effects of austempering on the microstructure, mechanical properties (micro hardness, impact energy and tensile strength) and corrosion behaviours of AISI 1018 low carbon steel were evaluated. The steel specimens were subjected to heat treatment by austenitizing at 830°C, maintained in this condition for 90 min before rapid cooling in a NaNO3 salt bath sustained at 300°C for isothermal transformation for additional 50 min and finally allowed to air cool to room temperature. The as-received and the austempered samples were tested for corrosion in both 0.5M aqueous acidic (HCl) and 0. 5M alkaline (NaOH) media. Microstructural investigation using scanning electron microscope (SEM) reveals transformation from ferrite/pearlite phases to bainite over the austempering process. Interestingly, significant improvements of 15.7% to 95.7% in the various mechanical properties (micro hardness, impact energy and tensile strength) and corrosion resistance in both media were obser...

FUOYE Journal of Engineering and Technology

Barite is a very important industrial minerals used as weighting material in the petroleum indust... more Barite is a very important industrial minerals used as weighting material in the petroleum industry. The nature of barite ores, geology of barite ores based on location were discussed. This paper presents top barite producing countries in the world, their production and consumption of barite, as well as their reserve. Despite all the barite deposits in Nigeria, which is approximately 15 million tonnes, it still imports barite from other countries for use in the drilling of oil and gas in Nigeria. This of course brings about unnecessary expenses been incurred by the government of Nigeria. Some of the challenges faced with the mining and processing of the Nigerian Barite were discussed. Proposed solutions to the mentioned challenges were also stated. The main challenge of the Nigerian barite is not with the American Petroleum Institute (API) standard, but the policies which do not favour investors. Investment by private companies into the mineral sector of Nigeria will bring about a l...

Engineering Applications of Diamond [Working Title]

Diamond-like carbon (DLC) coatings are amorphous carbon material which exhibits typical propertie... more Diamond-like carbon (DLC) coatings are amorphous carbon material which exhibits typical properties of diamond such as hardness and low coefficient of friction, characterized based on the sp3 bonded carbon and structure. The proportion of sp2 (graphetically) and sp3 (diamond-like) determines the properties of the DLC. This coating can be applied to automobile engine component in an attempt to provide energy efficiency by reducing friction and wear. However, DLC coatings are faced with issues of thermal instability caused by increasing temperature in the combustion engine of a vehicle. Therefore, it became necessary to seek ways of improving this coating to meetup with all tribological requirements that will be able to resist transformational change of the coating as the temperature increases. This chapter discusses the need for diamond-like carbon coatings for automobile engine applications, due to their ultra-low friction coefficient (<0.1) and excellent wear resistance (wear rat...

Proceedings on Engineering Sciences

Diamond-like carbon (DLC) coatings have become very attractive for various industrial application... more Diamond-like carbon (DLC) coatings have become very attractive for various industrial applications, such as cutting tools, automotive engines, biomedical implants, micro-electromechanical devices (MEMS). Due to their surface energies and ability to interact with lubricants to form surface protective films, good adhesion with substrate, increased wear resistance, improved electrical conductivity, decreased internal compressive stresses during deposition and thermal stability there are used in automobile components. In the automobile industry, DLC coatings are usually applied on combustion engine components such as piston, tappet, camshaft, piston rings and gudgeon pin, valve stem and head and rocker arm. DLC coatings helps in reducing friction and wear of the moving parts. However, there are challenges facing the use of DLC coated components during service, which are; internal compressive stresses, low adhesion and low thermal stability leading to failures such as rolling contact fatigue, micro-pitting, delamination, oxidation and scuffing. Hardness and internal compressive stress increase with increasing sp 3 content (sp 3 /sp 2) ratio in DLCs. Internal compressive stress for DLC coatings > 1GPa in tribological applications is not good, due to the elastic strain energy that drives fractures along the coating/substrate interface, leading to delamination through blistering. The addition of non-metals (Si, N, F or O) or metals (W, Cr, Ta, Ti, Mo or Cu) can improve thermal stability of DLC up to about 500 o C. Above, 500 o C transformation of sp3 to sp2 begins to occur leading to graphitization. The addition of metals increases the interfacial fracture toughness and moderates the internal stress by creating two (2) interface; substrate/adhesion layer interface and adhesion layer/functional coating interface. This present paper will discuss the various failures that occur on DLC coatings such as internal compressive stresses, low adhesion and low thermal stability of non-metal and metal doped DLC coatings, regarding their applications in automobile engines. The effect of annealing conditions, tribological properties of non-metal and metal doped DLC, effect of sp3/sp2 ratio, and possible ways of reducing these failures on DLC coatings be discussed also.

Corrosion Inhibitors [Working Title]

Internal and external corrosion affects oil and gas pipelines and were discussed in this chapter.... more Internal and external corrosion affects oil and gas pipelines and were discussed in this chapter. Corrosion inhibitors are one of the methods that can be used to achieve corrosion control and prevention. The main discussion in this chapter was the use of cassava plant (Manihot esculenta Crantz) extract nanoparticles (CPENPs) as an additive in coatings to serve as a green corrosion inhibitor for oil and gas pipeline. Trace elements, such as O, Si, Ca, K, Fe and S, which are hetero-atoms, have been identified in CPENPs. Elements like Si and Ca would also improve the strength of coatings as well as reduce corrosion rate of coated metals. It has also been revealed that CPENPs is composed of the following compounds SiO 2 , CaCO 3 , Ca 2 (SO 4) 2 H 2 O and CaC 2 O 4 (H 2 O), which would help in improving the mechanical properties of alloys, composites and coatings. SiO 2 if added to coatings will improve the coating hardness, while the presence of CaCO 3 in coatings will form a precipitate that will serve as a protective film on the surface of the metal, thereby protecting the metal from corrosion. The nature of bond and organic compounds that exist in the CPENPs was also discussed.

MRS Advances

A novel synthesis of Al (1xxx)/carbonised coconut shell (CCS) nanoparticles using a ball milling ... more A novel synthesis of Al (1xxx)/carbonised coconut shell (CCS) nanoparticles using a ball milling technique was investigated. Initial Al/0.1%CCS powders of an average size of 51.06μm was milled for a period of 70 h. The milled particles at 16, 46 and 70 h were characterized using X-ray diffractomer (XRD), scanning electron microscope (SEM), transmission electron microscope and UV-Vis spectrophotometer. Result revealed that the calculated particle crystallite size from XRD aided with Scherrer’s equation is consistent with particle image sizes obtained from SEM aided with software. TEM image depicted variation in orientation and appearance of the Al 1xxx/0.1% CCS nanoparticles at different milling time. The wide variation in the particle size is attributable to different ball impacts on the individual powders during the ball milling process. Increased maximum absorbance observed with the milled particles when compared with the initial powders is an indication of quantum/nanosizing effe...

Annals of Science and Technology

Characterization of synthesized cassava stem nanoparticles (CSNPs) was carried out using SEM/EDX ... more Characterization of synthesized cassava stem nanoparticles (CSNPs) was carried out using SEM/EDX and Gwyddion software, XRD and TEM for cassava stem (CS) ball milled at 36, 48, 60 and 72 h. The morphology study was done using SEM and the Gwyddion software was used to determine the particle size from the SEM images. The particle size range for the un-milled cassava stem (CS) was between 1.02+ 0.05 to 19.99+ 1.00 µm. After milling for 36, 48, 60 and 72 h the average particle size were 0.93+0.05 µm, 128.20+ 6.41, 111.20+ 5.56, 101.20 + 5.06 nm respectively. The particle size of 11.83+0.59 nm was obtained by XRD using Scherrer equation after milling for 72 h and the XRD results revealed the presence of compounds such as SiO 2 , CaCO 3 , Ca 3 SiO 5 and Al 2 O 3. Furthermore, TEM was used to determine nanoparticles after milling for 72 h and the particle size ranged from 8.35 + 0.42 to 51.74 + 2.59 nm for cassava stem nanoparticles (CSNPs) and EDX result showed trace element of O,Si, Ca, Al, K, Ti, Fe andP in the CS milled for 72 h.

MRS Advances

Synthesis and characterization of cassava bark nanoparticles (CBNPs) was carried out using ball m... more Synthesis and characterization of cassava bark nanoparticles (CBNPs) was carried out using ball milling at 36, 48, 60 and 72 hours. The morphology study was done using SEM and the Gwyddion software was used to determine the particle sizes from the SEM images. The particle distribution for the un-milled cassava bark (CB) was between 1.25 + 0.06 to 19.92 + 1.00 µm, while after milling for 36, 48, 60 and 72 hours the average particle size were 4.07 + 0.20, 4.00 + 0.20 µm, 80.90 + 4.05, 74.50 + 3.73 nm respectively. 13.68 + 0.68 nm was obtained by XRD using Scherrer equation after milling for 72 hours and the XRD results revealed the presence of compounds such as SiO2, CaCO3 and KAlSi3O8. TEM was used to determine nanoparticle size distribution after milling for 72 hours and the particle size ranged from 9.73 + 0.49 to 114.60 + 5.73 nm for cassava bark nanoparticles (CBNPs), EDX results showed trace element of Si, Ca, K, Fe, Al, O in the CB milled for 72hours.

Tribology in Industry, 2017

Characterization of synthesized cassava leaf nanoparticles (CLNPs) was carried out using SEM/EDX ... more Characterization of synthesized cassava leaf nanoparticles (CLNPs) was carried out using SEM/EDX and Gwyddion software, XRD and TEM for cassava leaves (CL) ball milled at 36, 48, 60 and 72 hours. The morphological study was done using SEM and the Gwyddion software was used to determine the particle sizes from the SEM images. The particle size range for the un-milled cassava leaves (CL) was between 1.88 + 0.09 to 19.53 + 0.98 µm. After milling for 36, 48, 60 and 72 hours the average particle sizes were 4.96 + 0.25, 3.51 + 0.18 µm, 86.90 + 4.35, 74.50 + 3.73 nm respectively. Crystallite size of 23.94 + 1.20 nm was obtained by XRD using Scherrer equation after milling for 72 hours and the XRD results revealed the presence of compounds such as SiO2, CaCO3, Ca2(SO4)2H2O and CaC2O4(H2O). Furthermore, TEM was used to determine nanoparticles after milling for 72 hours and the particle size ranged from 9.16 + 0.46 to 58.20 + 2.91 nm for cassava leaf nanoparticles (CLNPs) and EDX results showed trace element of O, Si, Ca, K, Fe and S in the CL milled for 72 hours. FTIR was also carried out to determine the nature of bond that exist in the organic compounds in CLNPs and GCMS analysis was used to reveal the organic compounds that were present in CLNPs. Anti-Corrosion coatings reduces corrosion activities to the bearest minimum.

SN Applied Sciences

The density, tensile properties at different gauge lengths, Weibull modulus, and water absorption... more The density, tensile properties at different gauge lengths, Weibull modulus, and water absorption at elevated temperatures of coir fibres of Sri Lanka are presented. The tensile strength and stiffness of these fibres were found to decrease by 51.0 and 68.0% respectively as the gauge length of the coir fibres increased from 20 to 100 mm at a constant cross-head displacement rate of 1 mm/minute. The elongation at break of these fibres increased from 33.3 to 62.5% as the gauge length increased from 20 to 100 mm. The porosity of the fibres is in the range of 32.9–48.1% with an average pore count of 130–475 and average cell diameter of 6.8–13.7 µm within the studied diameter range of 0.162–0.313 mm. The porosity of coir fibres was found to increase as the diameter increased. TGA and scanning electron microscopy of failed samples were conducted to analyse the failure modes and to observe the trend in changes in the mechanical properties.

Journal of The Institution of Engineers (India): Series D

Waste and Biomass Valorization

In this study, the effects of austempering on the microstructure, mechanical properties (micro ha... more In this study, the effects of austempering on the microstructure, mechanical properties (micro hardness, impact energy and tensile strength) and corrosion behaviours of AISI 1018 low carbon steel were evaluated. The steel specimens were subjected to heat treatment by austenitizing at 830°C, maintained in this condition for 90 min before rapid cooling in a NaNO3 salt bath sustained at 300°C for isothermal transformation for additional 50 min and finally allowed to air cool to room temperature. The as-received and the austempered samples were tested for corrosion in both 0.5M aqueous acidic (HCl) and 0. 5M alkaline (NaOH) media. Microstructural investigation using scanning electron microscope (SEM) reveals transformation from ferrite/pearlite phases to bainite over the austempering process. Interestingly, significant improvements of 15.7% to 95.7% in the various mechanical properties (micro hardness, impact energy and tensile strength) and corrosion resistance in both media were obser...

FUOYE Journal of Engineering and Technology

Barite is a very important industrial minerals used as weighting material in the petroleum indust... more Barite is a very important industrial minerals used as weighting material in the petroleum industry. The nature of barite ores, geology of barite ores based on location were discussed. This paper presents top barite producing countries in the world, their production and consumption of barite, as well as their reserve. Despite all the barite deposits in Nigeria, which is approximately 15 million tonnes, it still imports barite from other countries for use in the drilling of oil and gas in Nigeria. This of course brings about unnecessary expenses been incurred by the government of Nigeria. Some of the challenges faced with the mining and processing of the Nigerian Barite were discussed. Proposed solutions to the mentioned challenges were also stated. The main challenge of the Nigerian barite is not with the American Petroleum Institute (API) standard, but the policies which do not favour investors. Investment by private companies into the mineral sector of Nigeria will bring about a l...

Engineering Applications of Diamond [Working Title]

Diamond-like carbon (DLC) coatings are amorphous carbon material which exhibits typical propertie... more Diamond-like carbon (DLC) coatings are amorphous carbon material which exhibits typical properties of diamond such as hardness and low coefficient of friction, characterized based on the sp3 bonded carbon and structure. The proportion of sp2 (graphetically) and sp3 (diamond-like) determines the properties of the DLC. This coating can be applied to automobile engine component in an attempt to provide energy efficiency by reducing friction and wear. However, DLC coatings are faced with issues of thermal instability caused by increasing temperature in the combustion engine of a vehicle. Therefore, it became necessary to seek ways of improving this coating to meetup with all tribological requirements that will be able to resist transformational change of the coating as the temperature increases. This chapter discusses the need for diamond-like carbon coatings for automobile engine applications, due to their ultra-low friction coefficient (<0.1) and excellent wear resistance (wear rat...

Proceedings on Engineering Sciences

Diamond-like carbon (DLC) coatings have become very attractive for various industrial application... more Diamond-like carbon (DLC) coatings have become very attractive for various industrial applications, such as cutting tools, automotive engines, biomedical implants, micro-electromechanical devices (MEMS). Due to their surface energies and ability to interact with lubricants to form surface protective films, good adhesion with substrate, increased wear resistance, improved electrical conductivity, decreased internal compressive stresses during deposition and thermal stability there are used in automobile components. In the automobile industry, DLC coatings are usually applied on combustion engine components such as piston, tappet, camshaft, piston rings and gudgeon pin, valve stem and head and rocker arm. DLC coatings helps in reducing friction and wear of the moving parts. However, there are challenges facing the use of DLC coated components during service, which are; internal compressive stresses, low adhesion and low thermal stability leading to failures such as rolling contact fatigue, micro-pitting, delamination, oxidation and scuffing. Hardness and internal compressive stress increase with increasing sp 3 content (sp 3 /sp 2) ratio in DLCs. Internal compressive stress for DLC coatings > 1GPa in tribological applications is not good, due to the elastic strain energy that drives fractures along the coating/substrate interface, leading to delamination through blistering. The addition of non-metals (Si, N, F or O) or metals (W, Cr, Ta, Ti, Mo or Cu) can improve thermal stability of DLC up to about 500 o C. Above, 500 o C transformation of sp3 to sp2 begins to occur leading to graphitization. The addition of metals increases the interfacial fracture toughness and moderates the internal stress by creating two (2) interface; substrate/adhesion layer interface and adhesion layer/functional coating interface. This present paper will discuss the various failures that occur on DLC coatings such as internal compressive stresses, low adhesion and low thermal stability of non-metal and metal doped DLC coatings, regarding their applications in automobile engines. The effect of annealing conditions, tribological properties of non-metal and metal doped DLC, effect of sp3/sp2 ratio, and possible ways of reducing these failures on DLC coatings be discussed also.

Corrosion Inhibitors [Working Title]

Internal and external corrosion affects oil and gas pipelines and were discussed in this chapter.... more Internal and external corrosion affects oil and gas pipelines and were discussed in this chapter. Corrosion inhibitors are one of the methods that can be used to achieve corrosion control and prevention. The main discussion in this chapter was the use of cassava plant (Manihot esculenta Crantz) extract nanoparticles (CPENPs) as an additive in coatings to serve as a green corrosion inhibitor for oil and gas pipeline. Trace elements, such as O, Si, Ca, K, Fe and S, which are hetero-atoms, have been identified in CPENPs. Elements like Si and Ca would also improve the strength of coatings as well as reduce corrosion rate of coated metals. It has also been revealed that CPENPs is composed of the following compounds SiO 2 , CaCO 3 , Ca 2 (SO 4) 2 H 2 O and CaC 2 O 4 (H 2 O), which would help in improving the mechanical properties of alloys, composites and coatings. SiO 2 if added to coatings will improve the coating hardness, while the presence of CaCO 3 in coatings will form a precipitate that will serve as a protective film on the surface of the metal, thereby protecting the metal from corrosion. The nature of bond and organic compounds that exist in the CPENPs was also discussed.

MRS Advances

A novel synthesis of Al (1xxx)/carbonised coconut shell (CCS) nanoparticles using a ball milling ... more A novel synthesis of Al (1xxx)/carbonised coconut shell (CCS) nanoparticles using a ball milling technique was investigated. Initial Al/0.1%CCS powders of an average size of 51.06μm was milled for a period of 70 h. The milled particles at 16, 46 and 70 h were characterized using X-ray diffractomer (XRD), scanning electron microscope (SEM), transmission electron microscope and UV-Vis spectrophotometer. Result revealed that the calculated particle crystallite size from XRD aided with Scherrer’s equation is consistent with particle image sizes obtained from SEM aided with software. TEM image depicted variation in orientation and appearance of the Al 1xxx/0.1% CCS nanoparticles at different milling time. The wide variation in the particle size is attributable to different ball impacts on the individual powders during the ball milling process. Increased maximum absorbance observed with the milled particles when compared with the initial powders is an indication of quantum/nanosizing effe...